取得checkboxlist选中项的值；初始化CheckBoxList中哪些是选中了的

 /// <summary>
        /// 取得checkboxlist选中项的值
        /// </summary>
        /// <returns>选中项的值</returns>
        private string BindCheckBoxList()
        {
            string str = string.Empty;
            for (int i = 0; i < this.cbKeyWord.Items.Count; i++)
            {
                if (this.cbKeyWord.Items[i].Selected)
                {
                    str += cbKeyWord.Items[i].Value + ",";
                }
            }
            return !str.Equals(string.Empty) ? str.Remove(str.Length - 1, 1) : "";
        }

 /// <summary>
        /// 初始化CheckBoxList中哪些是选中了的         
        /// <param name="checkList">CheckBoxList</param>
        /// <param name="selval">选中了的值串例如："0,1,1,2,1"</param>
        /// <param name="separator">值串中使用的分割符例如"0,1,1,2,1"中的逗号</param>
        /// </summary>
        public static string SetChecked(CheckBoxList checkList, string selval, string separator)
        {
            //if (!selval.Equals(""))
            //{

            //}
            selval = separator + selval + separator;        //例如："0,1,1,2,1"->",0,1,1,2,1,"
            for (int i = 0; i < checkList.Items.Count; i++)
            {
                checkList.Items[i].Selected = false;
                string val = separator + checkList.Items[i].Value + separator;
                if (selval.IndexOf(val) != -1)
                {
                    checkList.Items[i].Selected = true;
                    selval = selval.Replace(val, separator);        //然后从原来的值串中删除已经选中了的
                    if (selval == separator)        //selval的最后一项也被选中的话，此时经过Replace后，只会剩下一个分隔符
                    {
                        selval += separator;        //添加一个分隔符
                    }
                }
            }
            selval = selval.Substring(1, selval.Length - 2);        //除去前后加的分割符号
            return selval;
        }